EP1004176A1 - Appareil de compensation des dispersions en fonction des longueurs d'ondes - Google Patents

Appareil de compensation des dispersions en fonction des longueurs d'ondes

Info

Publication number
EP1004176A1
EP1004176A1 EP99927544A EP99927544A EP1004176A1 EP 1004176 A1 EP1004176 A1 EP 1004176A1 EP 99927544 A EP99927544 A EP 99927544A EP 99927544 A EP99927544 A EP 99927544A EP 1004176 A1 EP1004176 A1 EP 1004176A1
Authority
EP
European Patent Office
Prior art keywords
optical
wavelength
segment
dispersion compensating
channels
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99927544A
Other languages
German (de)
English (en)
Inventor
Victor Mizrahi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ciena Corp
Original Assignee
Ciena Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ciena Corp filed Critical Ciena Corp
Publication of EP1004176A1 publication Critical patent/EP1004176A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29371—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion
    • G02B6/29374—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion in an optical light guide
    • G02B6/29376—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion in an optical light guide coupling light guides for controlling wavelength dispersion, e.g. by concatenation of two light guides having different dispersion properties
    • G02B6/29377—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion in an optical light guide coupling light guides for controlling wavelength dispersion, e.g. by concatenation of two light guides having different dispersion properties controlling dispersion around 1550 nm, i.e. S, C, L and U bands from 1460-1675 nm
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
    • G02B6/29392—Controlling dispersion
    • G02B6/29394—Compensating wavelength dispersion
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/2525—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using dispersion-compensating fibres
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/03—WDM arrangements
    • H04J14/0307—Multiplexers; Demultiplexers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
    • G02B6/29316—Light guides comprising a diffractive element, e.g. grating in or on the light guide such that diffracted light is confined in the light guide
    • G02B6/29317—Light guides of the optical fibre type
    • G02B6/29319—With a cascade of diffractive elements or of diffraction operations
    • G02B6/2932—With a cascade of diffractive elements or of diffraction operations comprising a directional router, e.g. directional coupler, circulator
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29346—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by wave or beam interference
    • G02B6/29358—Multiple beam interferometer external to a light guide, e.g. Fabry-Pérot, etalon, VIPA plate, OTDL plate, continuous interferometer, parallel plate resonator
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29346—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by wave or beam interference
    • G02B6/29361—Interference filters, e.g. multilayer coatings, thin film filters, dichroic splitters or mirrors based on multilayers, WDM filters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2210/00—Indexing scheme relating to optical transmission systems
    • H04B2210/25—Distortion or dispersion compensation
    • H04B2210/258—Distortion or dispersion compensation treating each wavelength or wavelength band separately

Definitions

  • the present invention generally relates to optical communication systems and more particularly to an apparatus for providing tailored multiple wavelength dispersion compensation.
  • Wavelength division multiplexing is a technique for increasing the capacity of existing fiber optic networks by transmitting a plurality of channels over a single waveguide medium.
  • WDM systems typically include a plurality of transmitters for transmitting modulated information signals on a designated one of a plurality of optical channels or wavelengths.
  • the transmitters used in WDM systems typically include semiconductor lasers each transmitting on a designated one of a plurality of wavelengths.
  • the selected wavelengths are usually within the 1.55 ⁇ m range which corresponds to an absorption minimum associated with silica-based fibers.
  • the channels are combined by a multiplexer at a first terminal and transmitted to a demultiplexer at a receiving terminal along a transmission fiber.
  • One or more amplifiers may be positioned along the transmission fiber to optically amplify the transmitted signals.
  • the demultiplexer separates the optical channels and supplies them to receiving circuitry which converts the optical signals into electrical signals for processing.
  • Dense WDM (DWDM) systems are also employed with this same general construction, but have a greater number of optical channels, typically with smaller channel spacings. The use of optical amplifiers in these types of systems solves the loss problem associated transmission over optical fiber, but does not solve the chromatic dispersion problem. Dispersion generally refers to the broadening of a transmitted pulse as it propagates down an optical fiber.
  • Group velocity dispersion is a parameter that expresses how much an optical pulse broadens when propagating inside an optical fiber and is expressed in units of ps/(km-nm).
  • the zero-dispersion wavelength ⁇ ZD is « 1.31 ⁇ m while a typical dispersion value for a wavelength in the 1.55 ⁇ m range transmitted along the same "standard” single mode fiber is 17ps/(km-nm).
  • the pulses spread they can overlap and interfere with each other, thereby impacting signal integrity. The effect becomes more pronounced at higher data rates. Pulses at different wavelengths typically suffer different amounts of dispersion.
  • Dispersion compensating fiber is a specialty optical fiber used to compensate for these dispersive effects encountered during signal transmission.
  • the specialty fiber has a dispersion characteristic of opposite sign to the optical fiber used for transmission.
  • Exemplary types of dispersion compensating fiber are commercially available from Lucent Technologies and/or Corning, Inc. While dispersion compensating fiber is generally a broadband solution to first order dispersion (dispersion slope), it does not properly compensate for second order dispersion. That is, the optimum length of these specialty fibers varies with channel wavelength. Thus, in a WDM system where multiple wavelengths are transmitted, no one length of dispersion compensating fiber precisely accommodates all channel wavelengths. To combat the effects of dispersion, some systems utilize dispersion shifted fiber.
  • Dispersion shifted fiber can provide a transmission path with close to zero dispersion, however, it suffers from certain nonlinearities, such as four wave mixing, which affect signal integrity.
  • Four wave mixing is a nonlinear effect that causes a plurality of waves propagating down a fiber at predetermined channel spacings to create a new wave at a particular frequency. This newly created wave causes crosstalk when it interferes with other channels within the signal channel plan. Therefore, with dispersion shifted fiber it is necessary to add back some dispersion to combat the effects of fiber nonlinearities. Examples of this type of fiber are TrueWave® from Lucent Technologies and "LS" fiber from Corning Inc. Accordingly, for transmission over standard optical fiber, dispersion compensating fiber is typically used at the receive end of a system to avoid costly installation of the specialty fiber within the transmission span.
  • an optical device comprising a transmission path capable of carrying a plurality of optical channels, each at a respective wavelength.
  • a wavelength branching element is coupled to the transmission path and is configured to separate at least one of the plurality of optical channels having a particular wavelength from the multiplexed signal.
  • a segment of dispersion compensating optical fiber is coupled to the wavelength branching element. The segment of optical fiber has a length corresponding to the particular wavelength associated with the at least one of the plurality of optical channels.
  • Fig. 1 illustrates a device for providing dispersion compensation using a demultiplexer and a multiplexer in accordance with the present invention.
  • Fig. 2 schematically illustrates an optical device in accordance with the present invention.
  • Fig. 3 is a schematic illustration of a wavelength branching unit in accordance with the present invention.
  • Fig. 4 schematically illustrates an alternative embodiment of a wavelength branching unit in accordance with the present invention.
  • Fig. 5 schematically illustrates an alternative embodiment of a wavelength branching unit in accordance with the present invention.
  • Fig. 6 schematically illustrates an optical device in accordance with the present invention.
  • an optical device is configured to separate one or more optical channels from a plurality of optical channels, each at a respective wavelength, and provides a length of dispersion compensating fiber for the one or more separated optical channels.
  • Fig. 1 illustrates a transmission path 5 which carries a plurality of optical channels, each at a respective wavelength ⁇ , ... ⁇ ⁇ , for example, in the 1550nrn range, to an optical demultiplexer 10.
  • Optical transmission path 5 is typically a single- mode silica-based fiber with a low loss window in the 1550nm range.
  • any optical waveguide which is capable of transporting multiple optical wavelengths can be employed as transmission path 5.
  • transmission path 5 is on the order of hundreds of kilometers long with optical amplifiers spaced approximately every one hundred kilometers, with a range of 30-130 kilometers being exemplary.
  • Demultiplexer 10 separates each channel from the multiplexed signal received via path 5 and supplies each signal to outputs 12,...12 N .
  • Each optical channel traverses a segment of dispersion compensating fiber 13 1 ...13 N disposed between demultiplexer 10 and multiplexer 15.
  • Each segment of fiber 13, ...13 N has lengths L, ...L N which corresponds to a length for a particular wavelength ⁇ , ... ⁇ N ; i.e., L, corresponds to a length of dispersion compensating fiber for wavelength ⁇ ,
  • L 2 corresponds to a length of dispersion compensating fiber for wavelength ⁇ , etc.
  • loss elements 14, ...14 may optionally be introduced downstream of fiber segments 13 , ...13 N to equalize these losses. Examples of loss element which can be used include attenuators commercially available from, for example, Gould, JDS Fitel and high loss fiber available, for example, from Lucent Technologies.
  • each signal channel traverses the respective segments of dispersion compensating fiber 13, ...13
  • the channels can be combined by multiplexer 15 if this configuration is disposed along a transmission path or in-line to supply the signals to optical path 20 for subsequent transmission.
  • multiplexer 15 can be avoided and each channel wavelength can be supplied to a downstream receiver for further processing. In this manner, each channel within the multiplexed optical signal traverses an associated length of dispersion compensating fiber segment providing a broadband solution.
  • Fig. 2 schematically illustrates an alternative embodiment in accordance with the present invention.
  • Optical device 30 includes one or more segments of dispersion compensating fiber 40, ...40 N disposed between wavelength branching units 45, ...45 N , respectively.
  • Each segment of dispersion compensating fiber 40, ...40 N has an associated length L, ...L N which corresponds to an adequate compensation length for a particular wavelength.
  • Optical device 30 can be disposed at or near a receiving terminal within a communications network where demultiplexing of the transmitted multiplexed signal is performed. If necessary, additional cleanup filters, for example interference filters, may be added for improved demultiplexing.
  • Optical transmission path 35 is configured to receive an optical signal including a plurality of multiplexed optical channels having wavelengths ⁇ , ... ⁇ N .
  • Transmission path 35 is typically a single-mode silica-based fiber having a corresponding absorption minimum in the 1.55 ⁇ m range. However, any optical waveguide which is capable of transporting multiple optical wavelengths can be employed as transmission path 35 in optical system 30.
  • Each of the wavelength branching units 45 , ...45 N receives a multiplexed signal at input ports 42, ...42 N .
  • Each branching unit is configured to select one or more channels having a particular wavelength from the multiplexed channels carried over path 35. The one or more selected channels are supplied to a respective output port 50, ...50 N .
  • Loss elements 14, ...14 N may optionally be coupled to wavelength branching unit output ports 50, ...50 N to equalize losses associated with dispersion compensating fiber segments 40, ...40 N .
  • the remaining channels not selected by the respective wavelength branching units 45, ...45 N are supplied to output ports 55, ...55 N .
  • segments of dispersion compensating fiber 40, ...40 N are used.
  • the multiplexed optical signal having channel wavelengths ⁇ , ... ⁇ N pass through segment of dispersion compensating fiber 40, the optical channels experience dispersion compensation.
  • the multiplexed optical signal is received by wavelength branching unit 45, at input port 42,.
  • Wavelength branching unit 45 selects an optical channel having wavelength ⁇ , from the multiplexed optical signal and supplies the selected channel to output port 50,.
  • the length L, of dispersion compensating fiber segment 40 corresponds to a length which adequately compensates for a particular wavelength, for example wavelength ⁇ , .
  • the remaining channels having wavelengths ⁇ 2 ... ⁇ N are supplied to output port 55, of wavelength branching unit 45, and pass to fiber segment 40 2 .
  • fiber segments 40, ...40 N have an associated length L, ...L N which, together with the preceding fiber segment length, corresponds to a length of dispersion compensating fiber adequate for a respective wavelength.
  • L, ...L N a length of dispersion compensating fiber adequate for a respective wavelength.
  • Table 1 illustrates exemplary wavelengths and corresponding dispersion compensating fiber lengths L, ...L N for transmission over 500km of non-zero dispersion shifted fiber having ⁇ 0 at 1515nm with dispersion slope of 0.08ps/nm 2 /km; the exemplary dispersion compensating fiber has dispersion of -lOOps/nm/km with dispersion slope of 0.
  • the respective lengths of dispersion compensating fiber are less than the amount of dispersion compensating fiber needed for optical channels having wavelength ⁇ 2 ... ⁇ N if the respective wavelengths did not undergo some degree of compensation from downstream fiber segments, e.g., fiber segment 40, having length L,.
  • Each of the optical channels experience the necessary dispersion compensation through fiber segments 40, ...40 N depending on their wavelengths before being selected or dropped by a wavelength branching unit 45, ...45 N .
  • optical device 30 provides a broadband dispersion compensating device which uses less dispersion compensating fiber for optical channels having wavelengths ⁇ , ... ⁇ N . thereby avoiding the use of excess amounts of costly dispersion compensating fiber.
  • the number of wavelength branching units 45, ...45 N is proportional to the number of optical channels selected from the multiplexed signal, for example within a WDM communications system where each branching unit can select one or more optical channels.
  • the number of dispersion compensating fiber segments 40, ...40 N , their lengths L, ...L N , and the amount of dispersion compensation desired may depend upon the number of channels to be selected and the wavelengths of each of the selected channels within the system channel plan.
  • an individual branching unit, for example, 45 can be configured to select more than one channel, e.g . channels having wavelengths ⁇ , and ⁇ N .
  • Dispersion compensating fiber segment 40 having length L, is of a sufficient length, together with fiber segment 40,, to compensate adequately for channels having wavelengths ⁇ , and ⁇ N selected by branching unit 45,.
  • the fiber segments 40, and 40 may combine to form an optimum length of fiber for a particular channel, e g., channel having wavelength ⁇ ,, and an adequate length for another channel, e ⁇ ., channel having wavelength ⁇ N .
  • a group of channels can be selected by a particular branching unit and lengths of dispersion compensating fiber associated with the branching unit can adequately compensate for the channels at their respective wavelengths.
  • Fig.3 schematically illustrates a wavelength branching unit 45, as an example of the wavelength branching units 45, ...45 N in accordance with the present invention.
  • Input port 42 is coupled to transmission path 35 and receives the multiplexed optical signal.
  • An optical transfer element 60 for example an optical circulator, includes first second and third ports 71, 72 and 73, respectively and is configured such that optical signals which enter first port 71 exit through second port 72 and optical signals which enter port 72 exit through third port 73.
  • the first circulator port 71 receives the multiplexed optical signal from optical path 35 and received by wavelength branching unit 45, via port 42,.
  • the multiplexed optical signal enters circulator 60 at first port 71 and rotates, in a clockwise direction toward second port 72.
  • Filtering element 65 is coupled to port 72 by way of optical fiber 62.
  • Filtering element 65 can be, for example, a Bragg grating, or other optical filtering device configured to select one or more wavelengths and allow the non-selected wavelengths to pass-through to line 66.
  • a Bragg grating comprises a series of photoinduced refractive index perturbations in an optical fiber which reflects optical signals within a selected wavelength band and transmits wavelengths outside of the selected wavelength band.
  • Filtering element 65 is tuned to have a low transmissivity and high reflection characteristic at a particular wavelength, for example ⁇ ,, and a high transmissivity or pass-through characteristic at wavelengths other than ⁇ ,. Accordingly, a portion of the multiplexed optical signal having wavelength ⁇ critique is reflected by filtering element 65, back to circulator port 2. The reflected portion of the signal travels clockwise in circulator 60 toward circulator port 3 and exits at output 3 onto optical path 50,. The portion of the multiplexed optical signal having wavelengths outside of ⁇ , pass-through filtering element 65, to line 66.
  • filtering elements 65, ...65 N are tuned to have a low transmissivity and high reflection characteristic at particular wavelengths, and a high transmissivity or pass- through characteristic at other wavelengths and can be, for example, Bragg gratings.
  • the remaining wavelengths not selected by filtering elements 65,...65 N are supplied to output port 55,.
  • one or more filtering elements 65, ...65 N can be employed to select a plurality of wavelengths from the multiplexed optical signal received via path 35.
  • each grating comprises a series of photoinduced refractive index perturbations in optical fiber 62 which reflects optical signals within a selected wavelength band and transmits wavelengths outside of the selected wavelength band as described above.
  • Bragg gratings suitable for use in wavelength branching units 45, ...45 N in accordance with the present invention are described in, inter alia, Morey et al., "Photoinduced Bragg Gratings in Optical Fibers,” Optics and Photonics News. February 1994, pp. 8-14.
  • broad chirped gratings may be selected to reflect a large wavelength band.
  • Strong gratings those that reflect over 95% of the incident wavelength, generally include a significant radiation mode loss band on the short wavelength side of the transmission/reflection spectrum.
  • Radiation mode loss describes optical signal loss due to scattering outside the core of the waveguide, including radiation scattered in the cladding of the waveguide. Consequently, it is desirable to ensure that the optical channels are not located within the radiation mode loss region for the grating.
  • the gratings are ordered such that the shortest channel wavelength is reflected first, in order up to the longest channel wavelength. This configuration eliminates the radiation mode loss effects which occur during reflection to port 72 of optical transfer device 60.
  • Fig. 4 schematically illustrates an alternative embodiment of wavelength branching unit 45 , as an example of the wavelength branching units 45 , ...45 , in accordance with the present invention.
  • Input port 42 is coupled to transmission path 35 and receives the multiplexed optical signal.
  • Optical filtering element 80 can be, for example, an interference filter configured to select one or more channels from the received multiplexed signal having wavelengths ⁇ , ... ⁇ N .
  • filtering element 80 reflects at least one optical channel having wavelength ⁇ , and supplies it to optical path 50,.
  • the remaining channels having wavelengths ⁇ ,... ⁇ N pass-through filtering element 80 to port 55,.
  • each filtering element 80 within wavelength branching units 45, ...45 N can be configured to select one or more optical channels having wavelengths ⁇ 2 ... ⁇ N .
  • Fig. 5 schematically illustrates an alternative embodiment of a wavelength branching unit 45, as an example of the wavelength branching units 45, ...45 in accordance with the present invention.
  • Input port 42 is coupled to transmission path 35 and receives the multiplexed optical signal.
  • Wavelength branching unit 45 includes an optical coupler 90 which supplies the multiplexed signal to filtering element 100.
  • Filtering element 100 is configured to reflect one or more channels from the received multiplexed signal having wavelengths ⁇ , ... ⁇ N , for example, channel having wavelength ⁇ , and supplies it to coupler 90 by way of optical path 92.
  • Filtering element 100 can be, for example a Fabry-Perot filter, a fiber grating, etc.
  • the reflected wavelength ⁇ is supplied to path 50, via coupler path 95.
  • the remaining channels having wavelengths ⁇ 2 ... ⁇ N pass-through filtering element 100 to port 55,.
  • Fig. 6 schematically illustrates an optical device where the dispersion compensation can be performed, for example, at the transmitting end and/or disposed along a transmission path within a communications system.
  • the channels are supplied to a multiplexer for subsequent transmission.
  • one or more segments of dispersion compensating fiber 40, ...40 are disposed between wavelength branching units 45, ...45 N , respectively.
  • a multiplexed optical signal having a plurality of channels at wavelengths ⁇ , ... ⁇ N , and ⁇ , are carried over path 35.
  • Segments of dispersion compensating fiber 40, ...40 N , 40 have associated lengths which correspond the an adequate compensation length for a particular wavelength as described above.
  • each channel is supplied to optical paths 50, ...50 N .
  • the channel or channels not selected by each branching unit 45, ...45 continue to propagate to the next branching unit.
  • the remaining channel, for example ⁇ , not selected by any of the branching units 45, ...45 N is supplied to fiber segment 40, coupled to output port 55 of branching unit 45 N .
  • Each of the selected channels are then supplied to multiplexer 120 where they are multiplexed and supplied to path 125 for subsequent propagation.

Landscapes

  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Optical Communication System (AREA)

Abstract

L'invention porte sur un dispositif optique séparant un ou plusieurs canaux optiques d'avec un ensemble de canaux optiques, chacun sur sa propre longueur d'ondes, et fixant une longueur de fibre optique de compensation de dispersion compensant idoinement le ou les canaux optiques séparés.
EP99927544A 1998-06-16 1999-06-16 Appareil de compensation des dispersions en fonction des longueurs d'ondes Withdrawn EP1004176A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US09/098,116 US6373609B1 (en) 1998-06-16 1998-06-16 Wavelength tailored dispersion compensation apparatus
US98116 1998-06-16
PCT/US1999/013512 WO1999066660A1 (fr) 1998-06-16 1999-06-16 Appareil de compensation des dispersions en fonction des longueurs d'ondes

Publications (1)

Publication Number Publication Date
EP1004176A1 true EP1004176A1 (fr) 2000-05-31

Family

ID=22267252

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99927544A Withdrawn EP1004176A1 (fr) 1998-06-16 1999-06-16 Appareil de compensation des dispersions en fonction des longueurs d'ondes

Country Status (4)

Country Link
US (1) US6373609B1 (fr)
EP (1) EP1004176A1 (fr)
CA (1) CA2301052A1 (fr)
WO (1) WO1999066660A1 (fr)

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100302634B1 (ko) * 1998-12-10 2001-11-30 서평원 Wdm광채널을모니터링하고분산을보상하는모듈및그모듈을포함한광증폭기
DE19915139A1 (de) * 1999-03-26 2000-09-28 Deutsche Telekom Ag Verfahren zur Dispersionskompensation gemeinsam übertragener optischer Signale mit unterschiedlichen Wellenlängen
US6507679B1 (en) * 1999-05-13 2003-01-14 Litton Systems, Inc. Long distance, all-optical telemetry for fiber optic sensor using remote optically pumped EDFAs
US6885824B1 (en) 2000-03-03 2005-04-26 Optical Coating Laboratory, Inc. Expandable optical array
US6577424B1 (en) * 2000-01-10 2003-06-10 Tyco Telecommunications (Us) Inc. Chromatic dispersion compensator providing dispersion compensation to select channels of a wavelength division multiplexed signal
US6353497B1 (en) 2000-03-03 2002-03-05 Optical Coating Laboratory, Inc. Integrated modular optical amplifier
JP3494110B2 (ja) * 2000-03-13 2004-02-03 日本電気株式会社 光分岐装置
US20020010928A1 (en) * 2000-04-24 2002-01-24 Ranjit Sahota Method and system for integrating internet advertising with television commercials
US9788058B2 (en) 2000-04-24 2017-10-10 Comcast Cable Communications Management, Llc Method and system for automatic insertion of interactive TV triggers into a broadcast data stream
US8296792B2 (en) 2000-04-24 2012-10-23 Tvworks, Llc Method and system to provide interactivity using an interactive channel bug
US8936101B2 (en) 2008-07-17 2015-01-20 Halliburton Energy Services, Inc. Interventionless set packer and setting method for same
US7702995B2 (en) 2000-04-24 2010-04-20 TVWorks, LLC. Method and system for transforming content for execution on multiple platforms
GB0012554D0 (en) * 2000-05-24 2000-07-12 Bae Systems Electronics Limite Improvements in or relating to optical delay lines
JP2002122515A (ja) * 2000-10-13 2002-04-26 Advantest Corp 光特性測定装置、方法、記録媒体
US6433924B1 (en) 2000-11-14 2002-08-13 Optical Coating Laboratory, Inc. Wavelength-selective optical amplifier
JP2002341157A (ja) 2001-03-15 2002-11-27 Fujikura Ltd 波長多重伝送路およびこれに用いる分散補償光ファイバ
ATE252793T1 (de) * 2001-05-14 2003-11-15 Cit Alcatel Optiches modul zur parallelen dispersionsverwaltung
JP3854836B2 (ja) * 2001-09-28 2006-12-06 キヤノン株式会社 垂直磁化膜を用いた磁気メモリの設計方法
US8935719B2 (en) 2011-08-25 2015-01-13 Comcast Cable Communications, Llc Application triggering
US9414114B2 (en) 2013-03-13 2016-08-09 Comcast Cable Holdings, Llc Selective interactivity
US11076205B2 (en) 2014-03-07 2021-07-27 Comcast Cable Communications, Llc Retrieving supplemental content
US20230084066A1 (en) * 2021-09-14 2023-03-16 Huawei Technologies Co., Ltd. System and method for dispersion compensation in fibered optical communication paths

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4405199A (en) 1981-02-11 1983-09-20 Ogle James W Method for enhancing signals transmitted over optical fibers
EP1156606A3 (fr) 1991-10-21 2004-02-04 Nec Corporation Système de transmission optique
JP3396270B2 (ja) 1993-08-10 2003-04-14 富士通株式会社 光分散補償方式
DE69528415T2 (de) * 1994-05-25 2003-06-18 At & T Corp., New York Optisches Übertragungssystem mit verstellbarer Dispersionskompensation
EP0732819A3 (fr) * 1995-03-15 1998-03-11 Sumitomo Electric Industries, Ltd. Compensateur de dispersion chromatique et système de communication optique compensant la dispersion chromatique
US6055081A (en) * 1995-03-15 2000-04-25 Sumitomo Electric Industries, Ltd. Chromatic dispersion compensator and chromatic dispersion compensating optical communication system
US5726784A (en) * 1995-05-11 1998-03-10 Ciena Corp. WDM optical communication system with remodulators and diverse optical transmitters
JPH08316938A (ja) * 1995-05-17 1996-11-29 Canon Inc 複数のチャンネルを多重して通信を行う光通信方法及び光通信システム
JPH0946318A (ja) * 1995-08-01 1997-02-14 Fujitsu Ltd 波長多重光伝送システム及び該伝送システムに用いる光送信装置
JPH09191290A (ja) 1996-01-10 1997-07-22 Nec Corp 光伝送路の波長分散補償システム
JPH10145298A (ja) 1996-11-08 1998-05-29 Kokusai Denshin Denwa Co Ltd <Kdd> 波長多重通信用光分波装置
US5841918A (en) * 1996-08-26 1998-11-24 Jds Fitel Inc. Wavelength and bandwidth tunable optical system
US6137604A (en) 1996-12-04 2000-10-24 Tyco Submarine Systems, Ltd. Chromatic dispersion compensation in wavelength division multiplexed optical transmission systems
JPH10170752A (ja) 1996-12-06 1998-06-26 Nec Corp 分散補償光回路
JP3050299B2 (ja) 1997-11-17 2000-06-12 日本電気株式会社 波長多重伝送装置
US6169616B1 (en) * 1998-06-04 2001-01-02 Avanex Corporation Optical and programmable fiber optic wavelength add/drop system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9966660A1 *

Also Published As

Publication number Publication date
CA2301052A1 (fr) 1999-12-23
US6373609B1 (en) 2002-04-16
WO1999066660A1 (fr) 1999-12-23

Similar Documents

Publication Publication Date Title
US6373609B1 (en) Wavelength tailored dispersion compensation apparatus
US5982518A (en) Optical add-drop multiplexers compatible with very dense WDM optical communication systems
EP1103107B1 (fr) Systeme bidirectionnel de compensation de la dispersion
US5748349A (en) Gratings-based optical add-drop multiplexers for WDM optical communication system
KR100383338B1 (ko) 파장분할다중화광섬유통신
USRE38289E1 (en) Chromatic dispersion compensation in wavelength division multiplexed optical transmission systems
US5943151A (en) Mehtod of selectively compensating for the chromatic dispersion of optical signals
US6459516B1 (en) Dense WDM add/drop multiplexer
US6348984B1 (en) Optical add/drop multiplexer
EP0777347B1 (fr) Système de transmission optique et répéteur optique
KR20010041551A (ko) 분산 보상용 광 소자
US6567577B2 (en) Method and apparatus for providing chromatic dispersion compensation in a wavelength division multiplexed optical transmission system
CA2241707C (fr) Circuit optique d&#39;extraction dote de compensation de temps de groupe
CA2375461A1 (fr) Procede et appareil pour la compensation de dispersion chromatique d&#39;ordre eleve
EP1202479A1 (fr) Systeme de compensation de la dispersion
US6633704B2 (en) Chromatic dispersion compensator
WO2002089363A1 (fr) Procede et systeme de compensation de la dispersion et de la pente de dispersion
US20040218862A1 (en) Wavelength dispersion compensator and optical transmission line
US6522455B1 (en) WDM optical communication system having a dispersion slope compensating element
JPH10170752A (ja) 分散補償光回路
US6577424B1 (en) Chromatic dispersion compensator providing dispersion compensation to select channels of a wavelength division multiplexed signal
JP4477778B2 (ja) フレキシブルな光マルチプレクサ
WO2001048961A1 (fr) Dispositif optique permettant d&#39;extraire et/ou d&#39;ajouter des signaux optiques
WO2002088805A1 (fr) Compensateur de dispersion chromatique
MXPA00011576A (en) Bidirectional dispersion compensation system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20000223

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE FR GB IT NL SE

17Q First examination report despatched

Effective date: 20030731

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20050930